Self-sealing of claystone under X-ray nanotomography

2018 ◽  
Vol 482 (1) ◽  
pp. 213-223 ◽  
Author(s):  
Richard Giot ◽  
Christophe Auvray ◽  
Jean Talandier
Keyword(s):  
Small Volume ◽  
The Body ◽  
The Self ◽  
Carbonate Content ◽  
X Rays ◽  
Two Phase ◽  
X Ray ◽  
Sealing Capacity ◽  
Crack Volume ◽  
Cylindrical Samples

AbstractSelf-sealing tests were carried out on cylindrical samples artificially cracked on one-third of the diameter with a perfectly controlled aperture. Water was then injected into the crack. An innovative cell was used that had been developed, the body of which is transparent to X-rays. The sample could fully rotate in the nanotomograph, allowing a 3D reconstruction of images before, during and after tests, a visualization of the evolution of the cracked zone, and a quantification of the variations in crack volume during self-sealing. Permeability measurements were made to quantify the influence of self-sealing on flows. In the present work, two facies of claystone with different CaCO3 contents were tested. In the clay-rich sample, an important but not total, reduction in volume was observed, as well as a large decrease in permeability, even if a safe claystone value was not recovered and a two-phase kinematic occurred. On the CaCO3-rich samples, a small volume reduction of the fracture was observed with a small decrease in water permeability. The influence of the mineralogy on the self-sealing capacity of the claystone was demonstrated and a threshold of carbonate content of around 40% was exhibited to discriminate samples able to self-seal from those that were not.

X-ray micro tomography in the scanning electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 106-107 ◽  
Author(s):  
W. Brünger
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Target Surface ◽  
The Body ◽  
X Rays ◽  
Cross Sectional ◽  
X Ray ◽  
Micro Tomography ◽  
Scanning Electron

Reconstructive tomography is a new technique in diagnostic radiology for imaging cross-sectional planes of the human body /1/. A collimated beam of X-rays is scanned through a thin slice of the body and the transmitted intensity is recorded by a detector giving a linear shadow graph or projection (see fig. 1). Many of these projections at different angles are used to reconstruct the body-layer, usually with the aid of a computer. The picture element size of present tomographic scanners is approximately 1.1 mm2.Micro tomography can be realized using the very fine X-ray source generated by the focused electron beam of a scanning electron microscope (see fig. 2). The translation of the X-ray source is done by a line scan of the electron beam on a polished target surface /2/. Projections at different angles are produced by rotating the object.During the registration of a single scan the electron beam is deflected in one direction only, while both deflections are operating in the display tube.

SURFACE SEGREGATION STUDIES OF SOFC CATHODES: COMBINING SOFT X-RAYS AND ELECTROCHEMICAL IMPEDENCE SPECTROSCOPY

2009 ◽  
Vol 1217 ◽  
Author(s):  
Lincoln Miara ◽  
Louis Piper ◽  
Jacob Nathan Davis ◽  
Laxmikant Saraf ◽  
Tiffany Kaspar ◽  
...  
Keyword(s):  
Single Crystal ◽  
Surface Segregation ◽  
Elevated Temperatures ◽  
Electrochemical Impedance ◽  
Lanthanum Manganite ◽  
X Rays ◽  
Two Phase ◽  
X Ray ◽  
Cation Migration ◽  
X Ray Absorption

AbstractA system to grow heteroepitaxial thin-films of solid oxide fuel cell (SOFC) cathodes on single crystal substrates was developed. The cathode composition investigated was 20% strontium-doped lanthanum manganite (LSM) grown by pulsed laser deposition (PLD) on single crystal (111) yttria-stabilized zirconia (YSZ) substrates. By combining electrochemical impedance spectroscopy (EIS) with x-ray photoemission spectroscopy (XPS) and x-ray absorption spectroscopy XAS measurements, we conclude that electrically driven cation migration away from the two-phase gas-cathode interface results in improved electrochemical performance. Our results provide support to the premise that the removal of surface passivating phases containing Sr2+ and Mn2+, which readily form at elevated temperatures even in O2 atmospheric pressures, is responsible for the improved cathodic performance upon application of a bias.

Implementation of the self-consistent Kröner–Eshelby model for the calculation of X-ray elastic constants for any crystal symmetry

2019 ◽  
Vol 34 (2) ◽  
pp. 103-109
Author(s):  
Arnold C. Vermeulen ◽  
Christopher M. Kube ◽  
Nicholas Norberg
Keyword(s):  
Elastic Constants ◽  
Ultrasonic Waves ◽  
The Self ◽  
Crystal Symmetry ◽  
Intermediate Step ◽  
X Rays ◽  
X Ray ◽  
Eshelby Inclusion ◽  
Eshelby Model ◽  
Self Consistent

In this paper, we will report about the implementation of the self-consistent Kröner–Eshelby model for the calculation of X-ray elastic constants for general, triclinic crystal symmetry. With applying appropriate symmetry relations, the point groups of higher crystal symmetries are covered as well. This simplifies the implementation effort to cover the calculations for any crystal symmetry. In the literature, several models can be found to estimate the polycrystalline elastic properties from single crystal elastic constants. In general, this is an intermediate step toward the calculation of the polycrystalline response to different techniques using X-rays, neutrons, or ultrasonic waves. In the case of X-ray residual stress analysis, the final goal is the calculation of X-ray Elastic constants. Contrary to the models of Reuss, Voigt, and Hill, the Kröner–Eshelby model has the benefit that, because of the implementation of the Eshelby inclusion model, it can be expanded to cover more complicated systems that exhibit multiple phases, inclusions or pores and that these can be optionally combined with a polycrystalline matrix that is anisotropic, i.e., contains texture. We will discuss a recent theoretical development where the approaches of calculating bounds of Reuss and Voigt, the tighter bounds of Hashin–Shtrikman and Dederichs–Zeller are brought together in one unifying model that converges to the self-consistent solution of Kröner–Eshelby. For the implementation of the Kröner–Eshelby model the well-known Voigt notation is adopted. The 4-rank tensor operations have been rewritten into 2-rank matrix operations. The practical difficulties of the Voigt notation, as usually concealed in the scientific literature, will be discussed. Last, we will show a practical X-ray example in which the various models are applied and compared.

scholarly journals STUDIES ON DECREASING THE REACTION OF NORMAL SKIN TO DESTRUCTIVE DOSES OF X-RAYS BY PHARMACOLOGICAL MEANS AND ON THE MECHANISM INVOLVED

1921 ◽  
Vol 33 (6) ◽  
pp. 791-813 ◽  
Author(s):  
John Auer ◽  
William D. Witherbee
Keyword(s):  
Anaphylactic Reaction ◽  
Acute Inflammation ◽  
Standard Dose ◽  
Normal Skin ◽  
Horse Serum ◽  
Previous Treatment ◽  
The Body ◽  
X Rays ◽  
General Hypothesis ◽  
X Ray

When a fixed area of the ears of rabbits is subjected to the action of a standard destructive dose of x-rays (30 skin units) the type of reaction resulting depends upon the previous treatment of the rabbit. (1) In normal rabbits a mild acute inflammation develops in the x-rayed area which leads at once to a perforating gangrene within an average of 15 days. (2) If rabbits are x-rayed and about 2 weeks later injected with horse serum for the first time, a mild acute inflammation appears which heals for a time; then a second, subacute inflammation sets in which leads to a perforating gangrene. The average time of the process from the first inflammation to gangrene is 32 days. (3) If rabbits are sensitized with horse serum and 10 days later are exposed locally to the standard dose of x-rays, the ensuing ear reaction is either similar to the second reaction described above, except that it may last up to 110 days, or the first inflammation leads to a healing which may be apparently permanent (340 + days). (4) If rabbits are first sensitized with horse serum, exposed locally to the standard dose of x-rays 10 days later, and 13 days after the x-ray treatment reinjected with horse serum, the reaction of the x-rayed area of the ears is in general similar to the second reaction described above (inflammation—healing—inflammation—gangrene). The average time of the whole process is about 42 days. On the basis of the general hypothesis that an anaphylactic reaction is initiated in the body when the specific antibody meets its antigen, and that both antibody and antigen are rendered more or less functionally inert by their interaction, the following inferences may be drawn from our experimental results. (1) The protection from the effects of a standard destructive dose of x-rays which a previous sensitization confers, is referable to the presence of anaphylactic antibodies in the x-rayed area. (2) This protection is largely due to the anaphylactic antibodies which are anchored in the x-rayed area, and not to those which are free in the circulation. (3) An anaphylactic reaction renders the anchored anaphylactic antibodies largely impotent as protective factors against the standard destructive x-ray dose, even though sensitization preceded exposure to the x-rays. (4) An area treated with the standard destructive dose of x-rays is unable to produce or to anchor a sufficient amount of anaphylactic antibodies for protection from necrosis, when the x-ray treatment precedes the sensitization, or when the locally anchored anaphylactic antibodies are rendered functionally inactive by a general anaphylactic reaction. It is possible that the procedure of increasing the resistance of the skin to a destructive dose of x-rays by means of a previous sensitization with protein may be applicable in the treatment of certain types of inoperable disease, when it is important to use massive doses of x-rays. Animals which have been sensitized, or sensitized and reinjected with any undenatured alien protein, should not be reemployed as normal controls in any investigation unless trial has shown that these proteinized animals react quantitatively and qualitatively like normal animals. The presence of an abnormal reactor in a group of supposedly normal animals may be an indication of a previous proteinization.

scholarly journals X-ray densitometric indices of proximal phalanx, medial phalanx and ungular pelvic limb bones as criteria for age diagnosis of cattle in forensic veterinary expertise

2019 ◽  
Vol 10 (2) ◽  
pp. 197-202
Author(s):  
I. V. Yatsenko ◽  
S. A. Tkachuk ◽  
L. V. Busol ◽  
M. M. Bondarevsky ◽  
I. V. Zabarna ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Proximal Phalanx ◽  
The Body ◽  
Heterogeneous Structure ◽  
Tubular Bone ◽  
X Rays ◽  
X Ray ◽  
Limb Bones ◽  
Pelvic Limb

Morphological parameters of biological material are extremely informative in diagnostic studies, in particular, to determine the species, sex, time of death, the term of burial. The most informative object for these tasks is the skeleton, because changes in the bones are stored for a long time, while soft tissue is subjected to rotting. Bone tissue is the most durable, but at the same time, it is very labile and reacts to all metabolic processes in the body. The object of the study was proximal phalanx, medial phalanx and ungular bone of the pelvic limb of cattle ranging in age from newborn to 12 years old. Radiography of the proximal phalanx, medial phalanx and ungular bones of the pelvic limb was performed on the Arman apparatus. The bones were subjected to X-ray in the lateromedial projection. The inner and outer sections of the tubular bone were determined. The mathematical modeling of the interaction of X-rays and the cortical layer of bones of fingers (proximal phalanx, medial phalanx and ungular) of cattle was carried out in this work. It is established that this process is described by Bouger's law. The physico-mathematical model of proximal phalanx, medial phalanx and ungular bones has been calculated, on the basis of which it was possible to calculate the X-ray densitometric indices of these bones of cattle. The age features of dynamics of X-ray densitometric indices of the proximal phalanx, medial phalanx and ungular bones were established and a method of determining the age of cattle according to this criterion was proposed. A mathematical model for the proximal phalanx, medial phalanx and ungular bones of the pelvic limbs of cattle that can be applied in X-ray densitometry uses: for the average third proximal phalanx – section of heterogeneous tubular structure modeled by a semicircle; for a medial phalanx bone – a section of a triangular shape; for the ungular bone – a heterogeneous structure, the plantar surface is inscribed in a rectangle. The process of interaction of X-rays with the bone structure of the examined pelvic limb bones can be described by Bouguer's law. The developed mathematical modeling of this interaction and the algorithm for its analysis is the basis for determining the age of cattle for X-ray densitometric indices of the proximal phalanx, medial phalanx and ungular bones of pelvic limbs. By X-ray densitometry of the proximal phalanx and medial phalanx bones of the pelvic limbs extremities one can diagnose the age of bovine animals from birth to 5 years, but according to ungular bones – from birth to 10 years. X-ray densitometry of medial phalanx and ungular bones of pelvic limbs can be used for diagnosing bovine cattle in a complex with other morphological, chemical and physical methods of investigation.

scholarly journals Thermal Or Non–Thermal X–Rays From AGNs?

1994 ◽  
Vol 159 ◽  
pp. 33-36
Author(s):  
Gabriele Ghisellini ◽  
Francesco Haardt
Keyword(s):  
High Energy ◽  
Spectral Shape ◽  
X Rays ◽  
Two Phase ◽  
X Ray ◽  
Galactic Black Hole ◽  
Phase Models ◽  
Hot Corona ◽  
High Energy Emission ◽  
Cold Matter

Recent data from OSSE on CGRO and SIGMA on GRANAT challenge the non-thermal interpretation of the origin of the high energy emission of AGNs, showing that the hard X-ray spectra of several Seyfert AGN are steep like those of Galactic black hole candidates. Thermal models are therefore favoured. Two–phase models, in which a hot corona is placed above a relatively cold accretion disk can account for the observed X–ray spectra and the correlated variability in the UV and X–ray bands. Cold matter, both in the vicinity of the nucleous, and located further away in the torus surrounding the nucleous, may modify substantially the spectrum with important consequences on the expected variability and spectral shape.

scholarly journals X-ray induced photodynamic therapy with copper-cysteamine nanoparticles in mice tumors

2019 ◽  
Vol 116 (34) ◽  
pp. 16823-16828 ◽  
Author(s):  
Samana Shrestha ◽  
Jing Wu ◽  
Bindeshwar Sah ◽  
Adam Vanasse ◽  
Leon N Cooper ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Treatment Method ◽  
The Body ◽  
Target Cells ◽  
X Rays ◽  
X Ray ◽  
Mouse Tumors ◽  
Study Results ◽  
New Type

Photodynamic therapy (PDT), a treatment that uses a photosensitizer, molecular oxygen, and light to kill target cells, is a promising cancer treatment method. However, a limitation of PDT is its dependence on light that is not highly penetrating, precluding the treatment of tumors located deep in the body. Copper-cysteamine nanoparticles are a new type of photosensitizer that can generate cytotoxic singlet oxygen molecules upon activation by X-rays. In this paper, we report on the use of copper-cysteamine nanoparticles, designed to be targeted to tumors, for X-ray–induced PDT. In an in vivo study, results show a statistically significant reduction in tumor size under X-ray activation of pH-low insertion peptide–conjugated, copper-cysteamine nanoparticles in mouse tumors. This work confirms the effectiveness of copper-cysteamine nanoparticles as a photosensitizer when activated by radiation and suggests that these Cu-Cy nanoparticles may be good candidates for PDT in deeply seated tumors when combined with X-rays and conjugated to a tumor-targeting molecule.

scholarly journals IMAGE SEGMENTATION OF CHEST X-RAYS FOR ABNORMALITY PATTERN RECOGNATION IN LUNGS USING FUZZY C-MEANS METHOD

2018 ◽  
Vol 2 (2) ◽  
pp. 13-23
Author(s):  
Matheus Alvian Wikanargo ◽  
Angelina Pramana Thenata
Keyword(s):  
Image Segmentation ◽  
The Body ◽  
Normal Lung ◽  
X Rays ◽  
Processing Stage ◽  
X Ray ◽  
Fuzzy C Means ◽  
Segmented Image ◽  
Chest X Ray ◽  
Normal Lungs

The lungs are one of the important and vital organs in the body that function as a respiratory system process. One way to detect lung disease is to do an X-rays test. Chest X-ray is a radiographic projection to detect abnormalities in lung organ by using x-ray radiation. In the process of diagnosing, doctors see the condition of the results of Chest X-rays in the form of a thorax image (chest) to know the patient has an abnormal or normal lung. However, doctors' diagnosis of chest X-rays results-based abnormalities is likely to differ depending on the doctor's abilities and experience. This problem is expected to be solved by segmenting the lung image to help make the diagnosis appropriately. The purpose of this study is to conduct an analysis that can differentiate abnormal and normal lungs. The process of recognition of these patterns consists of the pre-processing stage of image segmentation by using morphology and then proceed to grouping by using fuzzy c-means method to express the pattern of the already segmented image. This research produces normal and abnormal lung images that can be identified with an accuracy of 80%.

scholarly journals Recent Development in X-Ray Imaging Technology: Future and Challenges

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Xiangyu Ou ◽  
Xue Chen ◽  
Xianning Xu ◽  
Lili Xie ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
High Performance ◽  
Low Cost ◽  
Rapid Development ◽  
The Body ◽  
Future Research ◽  
X Rays ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
X Ray Imaging ◽  
Imaging Performance

X-ray imaging is a low-cost, powerful technology that has been extensively used in medical diagnosis and industrial nondestructive inspection. The ability of X-rays to penetrate through the body presents great advances for noninvasive imaging of its internal structure. In particular, the technological importance of X-ray imaging has led to the rapid development of high-performance X-ray detectors and the associated imaging applications. Here, we present an overview of the recent development of X-ray imaging-related technologies since the discovery of X-rays in the 1890s and discuss the fundamental mechanism of diverse X-ray imaging instruments, as well as their advantages and disadvantages on X-ray imaging performance. We also highlight various applications of advanced X-ray imaging in a diversity of fields. We further discuss future research directions and challenges in developing advanced next-generation materials that are crucial to the fabrication of flexible, low-dose, high-resolution X-ray imaging detectors.

Sign in / Sign up

Export Citation Format

Share Document